Upload & Sell: Off
I always feel like I've done something wrong if a portrait requires a lot of work. When I really get it right, only basic enhancements are necessary--color, contrast, skin tone, and maybe some skin smoothing or blemish removal. In Lightroom, I tend to first set a pleasing white balance, then tweak the exposure, contrast, and saturation, then I'll use the adjustment brush to add some brightness to the entire face with emphasis on the eyes. After that, in Photoshop, I might mask in some smooth areas of skin using the Portraiture plug-in and even out the skin tone with a brush set to "color" and 30% opacity. I do that by alt-clicking an area of skin with good color and then painting over other areas that need it (shadows that have picked up weird colors, redness, blotchy areas), and sometimes it can improve the look of a portrait even when the person's skin already looks good.
One thing I've learned - and maybe it's obvious, but it applies to any photo (and B&W ones) - is that it's best to find a level of brightness and contrast that suits the photo, then dodge, burn, or otherwise emphasize areas that have lost detail or need to stand out more. I used to try to reign everything in with global adjustments, but a shot can start to look really ugly when you try to (globally) lift every shadow or pull down every highlight for the sake of some dark eye sockets or an area of blown out hair.
Here's a before and after that had very little done to it. Granted, this is a professional model and makeup was used, but the concept is there I think.